Which of the following are signs of frostbite?

Frostbite primarily affects the skin and other tissues when exposed to freezing temperatures, leading to specific signs and symptoms. One of the classic signs of frostbite is pale and cold skin, which indicates that the blood flow to the area has been significantly reduced — a protective response by the body in extreme cold. The skin may also develop blisters as the tissue begins to sustain cellular damage, highlighting the severity of the frostbite.

Other options present symptoms that could be associated with various conditions but do not indicate frostbite. For instance, red, warm skin typically suggests conditions like a sunburn or an inflammatory response from conditions other than cold exposure. Swelling and fever usually relate to infections or inflammatory processes, rather than frostbite. Dark yellow skin and pain may indicate jaundice or other unrelated medical conditions. Therefore, the key indicators of frostbite are indeed pale, cold skin that may blister, making this the correct choice.